1 // unique_ptr implementation -*- C++ -*- 2 3 // Copyright (C) 2008-2013 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file bits/unique_ptr.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{memory} 28 */ 29 30 #ifndef _UNIQUE_PTR_H 31 #define _UNIQUE_PTR_H 1 32 33 #include <bits/c++config.h> 34 #include <debug/debug.h> 35 #include <type_traits> 36 #include <utility> 37 #include <tuple> 38 39 namespace std _GLIBCXX_VISIBILITY(default) 40 { 41 _GLIBCXX_BEGIN_NAMESPACE_VERSION 42 43 /** 44 * @addtogroup pointer_abstractions 45 * @{ 46 */ 47 48 #if _GLIBCXX_USE_DEPRECATED 49 template<typename> class auto_ptr; 50 #endif 51 52 /// Primary template, default_delete. 53 template<typename _Tp> 54 struct default_delete 55 { 56 constexpr default_delete() noexcept = default; 57 58 template<typename _Up, typename = typename 59 enable_if<is_convertible<_Up*, _Tp*>::value>::type> 60 default_delete(const default_delete<_Up>&) noexcept { } 61 62 void 63 operator()(_Tp* __ptr) const 64 { 65 static_assert(sizeof(_Tp)>0, 66 "can't delete pointer to incomplete type"); 67 delete __ptr; 68 } 69 }; 70 71 // _GLIBCXX_RESOLVE_LIB_DEFECTS 72 // DR 740 - omit specialization for array objects with a compile time length 73 /// Specialization, default_delete. 74 template<typename _Tp> 75 struct default_delete<_Tp[]> 76 { 77 private: 78 template<typename _Up> 79 using __remove_cv = typename remove_cv<_Up>::type; 80 81 // Like is_base_of<_Tp, _Up> but false if unqualified types are the same 82 template<typename _Up> 83 using __is_derived_Tp 84 = __and_< is_base_of<_Tp, _Up>, 85 __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >; 86 87 public: 88 constexpr default_delete() noexcept = default; 89 90 template<typename _Up, typename = typename 91 enable_if<!__is_derived_Tp<_Up>::value>::type> 92 default_delete(const default_delete<_Up[]>&) noexcept { } 93 94 void 95 operator()(_Tp* __ptr) const 96 { 97 static_assert(sizeof(_Tp)>0, 98 "can't delete pointer to incomplete type"); 99 delete [] __ptr; 100 } 101 102 template<typename _Up> 103 typename enable_if<__is_derived_Tp<_Up>::value>::type 104 operator()(_Up*) const = delete; 105 }; 106 107 /// 20.7.1.2 unique_ptr for single objects. 108 template <typename _Tp, typename _Dp = default_delete<_Tp> > 109 class unique_ptr 110 { 111 // use SFINAE to determine whether _Del::pointer exists 112 class _Pointer 113 { 114 template<typename _Up> 115 static typename _Up::pointer __test(typename _Up::pointer*); 116 117 template<typename _Up> 118 static _Tp* __test(...); 119 120 typedef typename remove_reference<_Dp>::type _Del; 121 122 public: 123 typedef decltype(__test<_Del>(0)) type; 124 }; 125 126 typedef std::tuple<typename _Pointer::type, _Dp> __tuple_type; 127 __tuple_type _M_t; 128 129 public: 130 typedef typename _Pointer::type pointer; 131 typedef _Tp element_type; 132 typedef _Dp deleter_type; 133 134 // Constructors. 135 constexpr unique_ptr() noexcept 136 : _M_t() 137 { static_assert(!is_pointer<deleter_type>::value, 138 "constructed with null function pointer deleter"); } 139 140 explicit 141 unique_ptr(pointer __p) noexcept 142 : _M_t(__p, deleter_type()) 143 { static_assert(!is_pointer<deleter_type>::value, 144 "constructed with null function pointer deleter"); } 145 146 unique_ptr(pointer __p, 147 typename conditional<is_reference<deleter_type>::value, 148 deleter_type, const deleter_type&>::type __d) noexcept 149 : _M_t(__p, __d) { } 150 151 unique_ptr(pointer __p, 152 typename remove_reference<deleter_type>::type&& __d) noexcept 153 : _M_t(std::move(__p), std::move(__d)) 154 { static_assert(!std::is_reference<deleter_type>::value, 155 "rvalue deleter bound to reference"); } 156 157 constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } 158 159 // Move constructors. 160 unique_ptr(unique_ptr&& __u) noexcept 161 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } 162 163 template<typename _Up, typename _Ep, typename = _Require< 164 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>, 165 __not_<is_array<_Up>>, 166 typename conditional<is_reference<_Dp>::value, 167 is_same<_Ep, _Dp>, 168 is_convertible<_Ep, _Dp>>::type>> 169 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 170 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 171 { } 172 173 #if _GLIBCXX_USE_DEPRECATED 174 template<typename _Up, typename = _Require< 175 is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>> 176 unique_ptr(auto_ptr<_Up>&& __u) noexcept; 177 #endif 178 179 // Destructor. 180 ~unique_ptr() noexcept 181 { 182 auto& __ptr = std::get<0>(_M_t); 183 if (__ptr != nullptr) 184 get_deleter()(__ptr); 185 __ptr = pointer(); 186 } 187 188 // Assignment. 189 unique_ptr& 190 operator=(unique_ptr&& __u) noexcept 191 { 192 reset(__u.release()); 193 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 194 return *this; 195 } 196 197 template<typename _Up, typename _Ep> 198 typename enable_if< __and_< 199 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>, 200 __not_<is_array<_Up>> 201 >::value, 202 unique_ptr&>::type 203 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 204 { 205 reset(__u.release()); 206 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 207 return *this; 208 } 209 210 unique_ptr& 211 operator=(nullptr_t) noexcept 212 { 213 reset(); 214 return *this; 215 } 216 217 // Observers. 218 typename add_lvalue_reference<element_type>::type 219 operator*() const 220 { 221 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 222 return *get(); 223 } 224 225 pointer 226 operator->() const noexcept 227 { 228 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 229 return get(); 230 } 231 232 pointer 233 get() const noexcept 234 { return std::get<0>(_M_t); } 235 236 deleter_type& 237 get_deleter() noexcept 238 { return std::get<1>(_M_t); } 239 240 const deleter_type& 241 get_deleter() const noexcept 242 { return std::get<1>(_M_t); } 243 244 explicit operator bool() const noexcept 245 { return get() == pointer() ? false : true; } 246 247 // Modifiers. 248 pointer 249 release() noexcept 250 { 251 pointer __p = get(); 252 std::get<0>(_M_t) = pointer(); 253 return __p; 254 } 255 256 void 257 reset(pointer __p = pointer()) noexcept 258 { 259 using std::swap; 260 swap(std::get<0>(_M_t), __p); 261 if (__p != pointer()) 262 get_deleter()(__p); 263 } 264 265 void 266 swap(unique_ptr& __u) noexcept 267 { 268 using std::swap; 269 swap(_M_t, __u._M_t); 270 } 271 272 // Disable copy from lvalue. 273 unique_ptr(const unique_ptr&) = delete; 274 unique_ptr& operator=(const unique_ptr&) = delete; 275 }; 276 277 /// 20.7.1.3 unique_ptr for array objects with a runtime length 278 // [unique.ptr.runtime] 279 // _GLIBCXX_RESOLVE_LIB_DEFECTS 280 // DR 740 - omit specialization for array objects with a compile time length 281 template<typename _Tp, typename _Dp> 282 class unique_ptr<_Tp[], _Dp> 283 { 284 // use SFINAE to determine whether _Del::pointer exists 285 class _Pointer 286 { 287 template<typename _Up> 288 static typename _Up::pointer __test(typename _Up::pointer*); 289 290 template<typename _Up> 291 static _Tp* __test(...); 292 293 typedef typename remove_reference<_Dp>::type _Del; 294 295 public: 296 typedef decltype(__test<_Del>(0)) type; 297 }; 298 299 typedef std::tuple<typename _Pointer::type, _Dp> __tuple_type; 300 __tuple_type _M_t; 301 302 template<typename _Up> 303 using __remove_cv = typename remove_cv<_Up>::type; 304 305 // like is_base_of<_Tp, _Up> but false if unqualified types are the same 306 template<typename _Up> 307 using __is_derived_Tp 308 = __and_< is_base_of<_Tp, _Up>, 309 __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >; 310 311 template<typename _Up, typename _Ep, 312 typename _Tp_pointer = typename _Pointer::type, 313 typename _Up_pointer = typename unique_ptr<_Up, _Ep>::pointer> 314 using __safe_conversion = __and_< 315 is_convertible<_Up_pointer, _Tp_pointer>, 316 is_array<_Up>, 317 __or_<__not_<is_pointer<_Up_pointer>>, 318 __not_<is_pointer<_Tp_pointer>>, 319 __not_<__is_derived_Tp<typename remove_extent<_Up>::type>> 320 > 321 >; 322 323 public: 324 typedef typename _Pointer::type pointer; 325 typedef _Tp element_type; 326 typedef _Dp deleter_type; 327 328 // Constructors. 329 constexpr unique_ptr() noexcept 330 : _M_t() 331 { static_assert(!std::is_pointer<deleter_type>::value, 332 "constructed with null function pointer deleter"); } 333 334 explicit 335 unique_ptr(pointer __p) noexcept 336 : _M_t(__p, deleter_type()) 337 { static_assert(!is_pointer<deleter_type>::value, 338 "constructed with null function pointer deleter"); } 339 340 template<typename _Up, typename = _Require<is_pointer<pointer>, 341 is_convertible<_Up*, pointer>, __is_derived_Tp<_Up>>> 342 explicit 343 unique_ptr(_Up* __p) = delete; 344 345 unique_ptr(pointer __p, 346 typename conditional<is_reference<deleter_type>::value, 347 deleter_type, const deleter_type&>::type __d) noexcept 348 : _M_t(__p, __d) { } 349 350 unique_ptr(pointer __p, typename 351 remove_reference<deleter_type>::type&& __d) noexcept 352 : _M_t(std::move(__p), std::move(__d)) 353 { static_assert(!is_reference<deleter_type>::value, 354 "rvalue deleter bound to reference"); } 355 356 // Move constructor. 357 unique_ptr(unique_ptr&& __u) noexcept 358 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } 359 360 constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } 361 362 template<typename _Up, typename _Ep, 363 typename = _Require<__safe_conversion<_Up, _Ep>, 364 typename conditional<is_reference<_Dp>::value, 365 is_same<_Ep, _Dp>, 366 is_convertible<_Ep, _Dp>>::type 367 >> 368 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 369 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 370 { } 371 372 // Destructor. 373 ~unique_ptr() 374 { 375 auto& __ptr = std::get<0>(_M_t); 376 if (__ptr != nullptr) 377 get_deleter()(__ptr); 378 __ptr = pointer(); 379 } 380 381 // Assignment. 382 unique_ptr& 383 operator=(unique_ptr&& __u) noexcept 384 { 385 reset(__u.release()); 386 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 387 return *this; 388 } 389 390 template<typename _Up, typename _Ep> 391 typename 392 enable_if<__safe_conversion<_Up, _Ep>::value, unique_ptr&>::type 393 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 394 { 395 reset(__u.release()); 396 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 397 return *this; 398 } 399 400 unique_ptr& 401 operator=(nullptr_t) noexcept 402 { 403 reset(); 404 return *this; 405 } 406 407 // Observers. 408 typename std::add_lvalue_reference<element_type>::type 409 operator[](size_t __i) const 410 { 411 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 412 return get()[__i]; 413 } 414 415 pointer 416 get() const noexcept 417 { return std::get<0>(_M_t); } 418 419 deleter_type& 420 get_deleter() noexcept 421 { return std::get<1>(_M_t); } 422 423 const deleter_type& 424 get_deleter() const noexcept 425 { return std::get<1>(_M_t); } 426 427 explicit operator bool() const noexcept 428 { return get() == pointer() ? false : true; } 429 430 // Modifiers. 431 pointer 432 release() noexcept 433 { 434 pointer __p = get(); 435 std::get<0>(_M_t) = pointer(); 436 return __p; 437 } 438 439 void 440 reset() noexcept 441 { reset(pointer()); } 442 443 void 444 reset(pointer __p) noexcept 445 { 446 using std::swap; 447 swap(std::get<0>(_M_t), __p); 448 if (__p != nullptr) 449 get_deleter()(__p); 450 } 451 452 template<typename _Up, typename = _Require<is_pointer<pointer>, 453 is_convertible<_Up*, pointer>, __is_derived_Tp<_Up>>> 454 void reset(_Up*) = delete; 455 456 void 457 swap(unique_ptr& __u) noexcept 458 { 459 using std::swap; 460 swap(_M_t, __u._M_t); 461 } 462 463 // Disable copy from lvalue. 464 unique_ptr(const unique_ptr&) = delete; 465 unique_ptr& operator=(const unique_ptr&) = delete; 466 467 // Disable construction from convertible pointer types. 468 template<typename _Up, typename = _Require<is_pointer<pointer>, 469 is_convertible<_Up*, pointer>, __is_derived_Tp<_Up>>> 470 unique_ptr(_Up*, typename 471 conditional<is_reference<deleter_type>::value, 472 deleter_type, const deleter_type&>::type) = delete; 473 474 template<typename _Up, typename = _Require<is_pointer<pointer>, 475 is_convertible<_Up*, pointer>, __is_derived_Tp<_Up>>> 476 unique_ptr(_Up*, typename 477 remove_reference<deleter_type>::type&&) = delete; 478 }; 479 480 template<typename _Tp, typename _Dp> 481 inline void 482 swap(unique_ptr<_Tp, _Dp>& __x, 483 unique_ptr<_Tp, _Dp>& __y) noexcept 484 { __x.swap(__y); } 485 486 template<typename _Tp, typename _Dp, 487 typename _Up, typename _Ep> 488 inline bool 489 operator==(const unique_ptr<_Tp, _Dp>& __x, 490 const unique_ptr<_Up, _Ep>& __y) 491 { return __x.get() == __y.get(); } 492 493 template<typename _Tp, typename _Dp> 494 inline bool 495 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 496 { return !__x; } 497 498 template<typename _Tp, typename _Dp> 499 inline bool 500 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 501 { return !__x; } 502 503 template<typename _Tp, typename _Dp, 504 typename _Up, typename _Ep> 505 inline bool 506 operator!=(const unique_ptr<_Tp, _Dp>& __x, 507 const unique_ptr<_Up, _Ep>& __y) 508 { return __x.get() != __y.get(); } 509 510 template<typename _Tp, typename _Dp> 511 inline bool 512 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 513 { return (bool)__x; } 514 515 template<typename _Tp, typename _Dp> 516 inline bool 517 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 518 { return (bool)__x; } 519 520 template<typename _Tp, typename _Dp, 521 typename _Up, typename _Ep> 522 inline bool 523 operator<(const unique_ptr<_Tp, _Dp>& __x, 524 const unique_ptr<_Up, _Ep>& __y) 525 { 526 typedef typename 527 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer, 528 typename unique_ptr<_Up, _Ep>::pointer>::type _CT; 529 return std::less<_CT>()(__x.get(), __y.get()); 530 } 531 532 template<typename _Tp, typename _Dp> 533 inline bool 534 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 535 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 536 nullptr); } 537 538 template<typename _Tp, typename _Dp> 539 inline bool 540 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 541 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 542 __x.get()); } 543 544 template<typename _Tp, typename _Dp, 545 typename _Up, typename _Ep> 546 inline bool 547 operator<=(const unique_ptr<_Tp, _Dp>& __x, 548 const unique_ptr<_Up, _Ep>& __y) 549 { return !(__y < __x); } 550 551 template<typename _Tp, typename _Dp> 552 inline bool 553 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 554 { return !(nullptr < __x); } 555 556 template<typename _Tp, typename _Dp> 557 inline bool 558 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 559 { return !(__x < nullptr); } 560 561 template<typename _Tp, typename _Dp, 562 typename _Up, typename _Ep> 563 inline bool 564 operator>(const unique_ptr<_Tp, _Dp>& __x, 565 const unique_ptr<_Up, _Ep>& __y) 566 { return (__y < __x); } 567 568 template<typename _Tp, typename _Dp> 569 inline bool 570 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 571 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 572 __x.get()); } 573 574 template<typename _Tp, typename _Dp> 575 inline bool 576 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 577 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 578 nullptr); } 579 580 template<typename _Tp, typename _Dp, 581 typename _Up, typename _Ep> 582 inline bool 583 operator>=(const unique_ptr<_Tp, _Dp>& __x, 584 const unique_ptr<_Up, _Ep>& __y) 585 { return !(__x < __y); } 586 587 template<typename _Tp, typename _Dp> 588 inline bool 589 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 590 { return !(__x < nullptr); } 591 592 template<typename _Tp, typename _Dp> 593 inline bool 594 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 595 { return !(nullptr < __x); } 596 597 /// std::hash specialization for unique_ptr. 598 template<typename _Tp, typename _Dp> 599 struct hash<unique_ptr<_Tp, _Dp>> 600 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>> 601 { 602 size_t 603 operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept 604 { 605 typedef unique_ptr<_Tp, _Dp> _UP; 606 return std::hash<typename _UP::pointer>()(__u.get()); 607 } 608 }; 609 610 // @} group pointer_abstractions 611 612 _GLIBCXX_END_NAMESPACE_VERSION 613 } // namespace 614 615 #endif /* _UNIQUE_PTR_H */ 616
